Armature for dynamo-electric machines



(No Model.)

C. F. BRUSH.

ARMATURE FOR DYNAMO ELEG-TRIO MACHINES.

` Patented Feb. 24, 1885.

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UNITED STATES PATENT OFFICE.

CHARLES F. BRUSH, OF CLEVELAND, OHIO.

ARMATURE FOR DYNAMO-ELECTRIC MACHINES.

SPECIFICATION forming part of Letters Patent No. 312,807, dated February 24, 1885.

Application filed May 13, ISF-l. (Xo model.)

To all whom it may concern:

Be it known that l, CHARLES F. BRUSH, of Cleveland, in the county of Cuyahoga and State of Ohio, have invented certain new and useful Improvements in Armatures for Dynamo-Electric Machines; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it pertains to make and use the same.

Figure l is a side view of half of the armature-ring as it appears before the wire is wound on. Fig. 2 is a top view of the same. Fig. 3 is a perspective view of the complete ring; and Fig. 4 is a section through the armature, showing one of the rivets. Fig. 5 shows a iilling-in strip.

The invention relates to certain improvements upon the armature describedin Patent No. 285,457, granted to me September 25, 1883. In the said patent I described an armaturecore built up of superposed bands or layers of soft iron, between which were interposed suitable eross pieces, which extended laterally to the full width of the armature, so as to form the projections between which the bobbins are wound. Vhen so constructed, the armaturecore is left with air-spaces extending` from one cross-piece to another between the layers, and it is the purpose of my present invention to fill up this space with a separate strip of iron, so as to still further add to the capacity of the machine by increasing` the amount of magnetic material in the armaturecore. In the aforesaid patent I showed how this space might be filled with a strip connecting the two cross-pieces on either side of each bobbin-space, the strip and cross-pieces being stamped or cut out of a piece of sheetiron in the form of the letter H. In the present construction, however, this cutting is saved, as the filling-in strip is made separate from the cross-pieces, and may be cut from ordinary band-iron.

My present improvement also relates to the rivets or bolts by means of which the layers or bands and the cross-pieces are held together, and it consists in insulating the rivets or bolts, in whole or in part, from the other metallic parts, so as to prevent the same from forminga path for the Foucault currents from one band to another, thereby diminishing the heating and increasing in a corresponding degree the efficiency of the machine.

In the drawings, A represents the base-ring upon which the band-iron is wound.

B indicates the layers of band iron, and C the interposed cross-pieces. The band-iron may be either wound as a continuous spiral, in the manner of a roll of ribbon, the crosspieces being interposed during the winding, or the layers may be built up in concentric rings, there being one or more separate pieces of band-iron to each ring. The cross-pieces gradually increase in width from the basering outward. so as to render the sides of the bobbin-spaces parallel.

D indicates the filling-in pieces, which are cut from ordinary band-iron, and after being bent, like the cross -pieces C, to correspond with the circular `form of the armature, they are interposed, with the cross-pieces, in the winding or building up of the armature, so as to lill the spaces between the bands from one cross-piece to another. The filling-in strips D may be omitted during the winding or building up of the core, and afterward driven into the openings left between the bands. I prefer to coat the cross-pieces C and filling-in strips D with Japan or other insulating Varnish before they are put into the armature, for the better security against Foucault currents. The same pieces may be also wrapped with paper, cloth, or other insulating envelope to further secure this object. The bands are secured to each other and to the base-ring by rivets or bolts E. F is an insulating sheath or bushing surrounding the shank of the rivet, and G is an insulating-washer under the outer head of the same. A metallic washer, II, is interposed between the rivet-head and the insulatingwasher to give sufficientbearing-surface. One end of the rivet may be left uninsulated, as shown, and, if desired, one rivet only of each pair may be insulated. Asuitable insulating material may be made from superposed layers of shellacked paper, the paper being rolled into the shape of a tube of a size to t closely the rivet and the hole drilled therefor.

It will be noticed that the cross-pieces C IOO all extend the full distance between the bobbins, this being in seine enses preferable.

I claim herein as my invention- 1. An armature formed of snperposed lztyers of band-iron having interposed between them laterally-projecting cross-pieces that form the side Walls of the hobbin-spnees, and separable lling-in strips interposed between the eross-pieees7 substantially as set forth.

2. An arnmturering formed of superposed layers or eonvolutions of band-iron, with laterally-projecting cross-pieces interposed hetween the same, said cross-pieces forming the side Walls of the bobbin-spaees, tnd rivets or bolts extending through both bi1-nds and erosspieces, and insulated in Whole or in psu-t therefrom, substantially :is set forth.

3. An armature-ring having its central part made up of snperposed layers of band-iron, and having lateral extensions forming the 2o hohbin-spaees, seid extensions consisting of interposed cross-pieces extending from bobbin to bohbin the full thickness of the ring, substantially ns set forth.

In testimony whereof I sign this speeiliezt- 2 5 tion, in the presence of two witnesses7 this 23d day of April, 188i.

CHARLES F. BRUSH.

Vitnesses:

E. B. Pnrmrrs, ALBERT E. LYNCH. 

